On a recent trip I was overwhelmed with all the choices offered at gas stations across the country; like pure-vs-alcohol enhanced, octane and cost. Stations called the alcohol blends ?Plus? and listed their octane a couple points higher, but varied the price- sometimes being 2% higher and sometimes 2% lower than pure gas. Prior articles about green fuels, like ethanol, indicate they contain up to 10% less energy and give less MPG than pure gas. I bailed on calculations during the trip and just bought the cheapest price which met the car?s octane needs. What is the price ratio or difference where an alcohol blend offers the better value, the higher MPG per dollar?
You did the right thing; buy the least expensive gas that your car needs, and pure gasoine will give you better mileage than alcohol blends.
I, likewise, gave up, and alternate between a major brand and our local cooperative. If I get a free wash with a fillup, I’ll go for that too.
the cheapest price which met the car?s octane needs.
That is the answer. If you have a choice, the lowest available ethanol % is best as the ethanol will slightly lower mileage.